Answer :
To simplify the equation, you need to put everything on one side and add the like terms.
4a + 3b = 6b - 9a
Put everything on the left side:
4a + 9a + 3b - 6b = 0
Then add like terms:
13a - 3b = 0
4a + 3b = 6b - 9a
Put everything on the left side:
4a + 9a + 3b - 6b = 0
Then add like terms:
13a - 3b = 0
